EPOXI/Deep Impact

All About Comets

Colliding & observing

The EPOXI and Deep Impact missions have provided scientists with extremely valuable data on the nature of comets. EPOXI was the second mission to use the Deep Impact vehicle for comet research. On Nov. 4, 2010, the spacecraft approached Comet Hartley 2 at a distance of about 700 kilometers (434 miles). The observation was the fifth time that a comet has been imaged that close, and the first time in history that two comets have been imaged with the same instruments and same spatial resolution.

Built for a July 2005 mission, the Deep Impact spacecraft collided with deep-space comet Tempel 1 and excavated material from the nucleus of the comet. Using its onboard instruments, Deep Impact observed the nucleus of the comet, giving scientists an unprecedented view of the characteristics of comets and the materials inside.

What we did

Mission prime contractor

We were the mission prime contractor for Deep Impact with responsibility for the two-part spacecraft: the Impactor spacecraft and Flyby spacecraft; and three high resolution cameras; algorithm development; environmental testing; and launch and mission support.

Many of our other instruments were also involved in recording the Deep Impact collision. Three of NASA’s Great Observatories – Hubble, Spitzer and Chandra – were tasked for the event. We played a significant role in all of these.

Crashing into a Comet

Ka-Boom!

The two-part spacecraft launched in tandem in Jan. 12, 2005 and separated 24 hours before reaching the target. The Impactor autonomously positioned itself on a crash course with the Tempel 1 comet.

With closing speeds of 23,000 mph, the Impactor’s active guidance system steered it to impact on a sunlit portion of the comet’s surface. As it closed in on Tempel 1, the Impactor’s camera relayed close-up images of the comet’s surface to the Flyby spacecraft for downlink to Earth. Meanwhile, the Flyby spacecraft used its two instruments to image the impact and then continued to photograph the comet as it followed its orbital path around the Sun. The primary science data was returned to Earth in near real-time, and all data was returned to Earth within one day of the encounter.